An Airborne Instantaneous Microwave Direction Finder, The (NL/ALD-A)
Abstract
An airborne wide-open direction finder which covers the frequency range of 2200 to 10, 000 me in two bands has been developed at the Naval Research Laboratory. The direction finder utilizes crystal-video detection and, being untuned, is capable of responding to all amplitude-modulated signals within the r-f band at any time. The system responds to signals of any polarization and presents bearings instantaneously on a 3-inch cathode-ray tube. It is designed primarily to detect radar signals from submarines and to give warning of the presence of potentially dangerous signals such as airborne intercept or ground-controlled intercept. The maximum instrumental bearing error of the direction finder is less than 8 degrees and is generally less than 6degrees. The bearing errors of the system installed on an aircraft are appreciably greater because of the critical effect of the reflections from the aircraft surfaces upon the field at the antenna. The sensitivity is sufficient to provide line of-sight or greater detection ranges against high-power shipborne or ground-based radars. Tests have shown that the direction finder is capable of handling a large number of near-simultaneous signals at one time and can be utilized very effectively in homing on intermittent radar signals. The power requirements of the system are moderate and the size and weight are small enough so that it can be installed in a carrier-type aircraft.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 03, 1955
- Accession Number
- AD1222137
Entities
People
- A. J. Jr Jesswein
- J. R. Gruber
- V. S. Rose
Organizations
- United States Naval Research Laboratory